]> git.cameronkatri.com Git - pw-darwin.git/blobdiff - libutil/gr_util.c
More prototype formatting fixes, struct member formatting fixes,
[pw-darwin.git] / libutil / gr_util.c
index 89f5fa385416d60487cc19e555a9e202eacffdf2..0173595c24d0fb3cad6b9a4329e3946ad15fbdfe 100644 (file)
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
+#include <sys/errno.h>
+#include <sys/stat.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <fcntl.h>
 #include <grp.h>
 #include <inttypes.h>
+#include <libutil.h>
+#include <paths.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
-#include <libutil.h>
+struct group_storage {
+       struct group     gr;
+       char            *members[];
+};
+
+static int lockfd = -1;
+static char group_dir[PATH_MAX];
+static char group_file[PATH_MAX];
+static char tempname[PATH_MAX];
+static int initialized;
+
+static const char group_line_format[] = "%s:%s:%ju:";
+
+/*
+ * Initialize statics
+ */
+int
+gr_init(const char *dir, const char *group)
+{
+       if (dir == NULL) {
+               strcpy(group_dir, _PATH_ETC);
+       } else {
+               if (strlen(dir) >= sizeof(group_dir)) {
+                       errno = ENAMETOOLONG;
+                       return (-1);
+               }
+               strcpy(group_dir, dir);
+       }
+
+       if (group == NULL) {
+               if (dir == NULL) {
+                       strcpy(group_file, _PATH_GROUP);
+               } else if (snprintf(group_file, sizeof(group_file), "%s/group",
+                       group_dir) > (int)sizeof(group_file)) {
+                       errno = ENAMETOOLONG;
+                       return (-1);
+               }
+       } else {
+               if (strlen(group) >= sizeof(group_file)) {
+                       errno = ENAMETOOLONG;
+                       return (-1);
+               }
+               strcpy(group_file, group);
+       }
+       initialized = 1;
+       return (0);
+}
+
+/*
+ * Lock the group file
+ */
+int
+gr_lock(void)
+{
+       if (*group_file == '\0')
+               return (-1);
+
+       for (;;) {
+               struct stat st;
+
+               lockfd = open(group_file, O_RDONLY, 0);
+               if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
+                       err(1, "%s", group_file);
+               if (flock(lockfd, LOCK_EX|LOCK_NB) == -1) {
+                       if (errno == EWOULDBLOCK) {
+                               errx(1, "the group file is busy");
+                       } else {
+                               err(1, "could not lock the group file: ");
+                       }
+               }
+               if (fstat(lockfd, &st) == -1)
+                       err(1, "fstat() failed: ");
+               if (st.st_nlink != 0)
+                       break;
+               close(lockfd);
+               lockfd = -1;
+       }
+       return (lockfd);
+}
+
+/*
+ * Create and open a presmuably safe temp file for editing group data
+ */
+int
+gr_tmp(int mfd)
+{
+       char buf[8192];
+       ssize_t nr;
+       const char *p;
+       int tfd;
+
+       if (*group_file == '\0')
+               return (-1);
+       if ((p = strrchr(group_file, '/')))
+               ++p;
+       else
+               p = group_file;
+       if (snprintf(tempname, sizeof(tempname), "%.*sgroup.XXXXXX",
+               (int)(p - group_file), group_file) >= (int)sizeof(tempname)) {
+               errno = ENAMETOOLONG;
+               return (-1);
+       }
+       if ((tfd = mkstemp(tempname)) == -1)
+               return (-1);
+       if (mfd != -1) {
+               while ((nr = read(mfd, buf, sizeof(buf))) > 0)
+                       if (write(tfd, buf, (size_t)nr) != nr)
+                               break;
+               if (nr != 0) {
+                       unlink(tempname);
+                       *tempname = '\0';
+                       close(tfd);
+                       return (-1);
+               }
+       }
+       return (tfd);
+}
+
+/*
+ * Copy the group file from one descriptor to another, replacing, deleting
+ * or adding a single record on the way.
+ */
+int
+gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
+{
+       char buf[8192], *end, *line, *p, *q, *r, t;
+       struct group *fgr;
+       const struct group *sgr;
+       size_t len;
+       int eof, readlen;
+
+       sgr = gr;
+       if (gr == NULL) {
+               line = NULL;
+               if (old_gr == NULL)
+                       return (-1);
+               sgr = old_gr;
+       } else if ((line = gr_make(gr)) == NULL)
+               return (-1);
+
+       eof = 0;
+       len = 0;
+       p = q = end = buf;
+       for (;;) {
+               /* find the end of the current line */
+               for (p = q; q < end && *q != '\0'; ++q)
+                       if (*q == '\n')
+                               break;
+
+               /* if we don't have a complete line, fill up the buffer */
+               if (q >= end) {
+                       if (eof)
+                               break;
+                       if ((size_t)(q - p) >= sizeof(buf)) {
+                               warnx("group line too long");
+                               errno = EINVAL; /* hack */
+                               goto err;
+                       }
+                       if (p < end) {
+                               q = memmove(buf, p, end -p);
+                               end -= p - buf;
+                       } else {
+                               p = q = end = buf;
+                       }
+                       readlen = read(ffd, end, sizeof(buf) - (end -buf));
+                       if (readlen == -1)
+                               goto err;
+                       else
+                               len = (size_t)readlen;
+                       if (len == 0 && p == buf)
+                               break;
+                       end += len;
+                       len = end - buf;
+                       if (len < (ssize_t)sizeof(buf)) {
+                               eof = 1;
+                               if (len > 0 && buf[len -1] != '\n')
+                                       ++len, *end++ = '\n';
+                       }
+                       continue;
+               }
 
+               /* is it a blank line or a comment? */
+               for (r = p; r < q && isspace(*r); ++r)
+                       /* nothing */;
+               if (r == q || *r == '#') {
+                       /* yep */
+                       if (write(tfd, p, q -p + 1) != q - p + 1)
+                               goto err;
+                       ++q;
+                       continue;
+               }
+
+               /* is it the one we're looking for? */
+
+               t = *q;
+               *q = '\0';
+
+               fgr = gr_scan(r);
+
+               /* fgr is either a struct group for the current line,
+                * or NULL if the line is malformed.
+                */
+
+               *q = t;
+               if (fgr == NULL || fgr->gr_gid != sgr->gr_gid) {
+                       /* nope */
+                       if (fgr != NULL)
+                               free(fgr);
+                       if (write(tfd, p, q - p + 1) != q - p + 1)
+                               goto err;
+                       ++q;
+                       continue;
+               }
+               if (old_gr && !gr_equal(fgr, old_gr)) {
+                       warnx("entry inconsistent");
+                       free(fgr);
+                       errno = EINVAL; /* hack */
+                       goto err;
+               }
+               free(fgr);
+
+               /* it is, replace or remove it */
+               if (line != NULL) {
+                       len = strlen(line);
+                       if (write(tfd, line, len) != (int) len)
+                               goto err;
+               } else {
+                       /* when removed, avoid the \n */
+                       q++;
+               }
+               /* we're done, just copy the rest over */
+               for (;;) {
+                       if (write(tfd, q, end - q) != end - q)
+                               goto err;
+                       q = buf;
+                       readlen = read(ffd, buf, sizeof(buf));
+                       if (readlen == 0)
+                               break;
+                       else
+                               len = (size_t)readlen;
+                       if (readlen == -1)
+                               goto err;
+                       end = buf + len;
+               }
+               goto done;
+       }
+
+       /* if we got here, we didn't find the old entry */
+       if (line == NULL) {
+               errno = ENOENT;
+               goto err;
+       }
+       len = strlen(line);
+       if ((size_t)write(tfd, line, len) != len ||
+          write(tfd, "\n", 1) != 1)
+               goto err;
+ done:
+       if (line != NULL)
+               free(line);
+       return (0);
+ err:
+       if (line != NULL)
+               free(line);
+       return (-1);
+}
+
+/*
+ * Regenerate the group file
+ */
+int
+gr_mkdb(void)
+{
+       return (rename(tempname, group_file));
+}
 
-static const char GroupLineFormat[] = "%s:%s:%ju:";
+/*
+ * Clean up. Preserver errno for the caller's convenience.
+ */
+void
+gr_fini(void)
+{
+       int serrno;
 
+       if (!initialized)
+               return;
+       initialized = 0;
+       serrno = errno;
+       if (*tempname != '\0') {
+               unlink(tempname);
+               *tempname = '\0';
+       }
+       if (lockfd != -1)
+               close(lockfd);
+       errno = serrno;
+}
 
 /*
  * Compares two struct group's.
@@ -47,41 +346,50 @@ static const char GroupLineFormat[] = "%s:%s:%ju:";
 int
 gr_equal(const struct group *gr1, const struct group *gr2)
 {
+       int gr1_ndx;
+       int gr2_ndx;
        bool found;
-       bool equal;
-       int gr1Ndx;
-       int gr2Ndx;
 
        /* Check that the non-member information is the same. */
-       equal = strcmp(gr1->gr_name, gr2->gr_name) == 0 &&
-           strcmp(gr1->gr_passwd, gr2->gr_passwd) == 0 &&
-           gr1->gr_gid == gr2->gr_gid;
+       if (gr1->gr_name == NULL || gr2->gr_name == NULL) {
+               if (gr1->gr_name != gr2->gr_name)
+                       return (false);
+       } else if (strcmp(gr1->gr_name, gr2->gr_name) != 0)
+               return (false);
+       if (gr1->gr_passwd == NULL || gr2->gr_passwd == NULL) {
+               if (gr1->gr_passwd != gr2->gr_passwd)
+                       return (false);
+       } else if (strcmp(gr1->gr_passwd, gr2->gr_passwd) != 0)
+               return (false);
+       if (gr1->gr_gid != gr2->gr_gid)
+               return (false);
 
        /* Check all members in both groups. */
-       if (equal) {
-               for (found = false, gr1Ndx = 0; gr1->gr_mem[gr1Ndx] != NULL;
-                   gr1Ndx++) {
-                       for (gr2Ndx = 0; gr2->gr_mem[gr2Ndx] != NULL; gr2Ndx++)
-                               if (strcmp(gr1->gr_mem[gr1Ndx],
-                                   gr2->gr_mem[gr2Ndx]) == 0) {
+       if (gr1->gr_mem == NULL || gr2->gr_mem == NULL) {
+               if (gr1->gr_mem != gr2->gr_mem)
+                       return (false);
+       } else {
+               for (found = false, gr1_ndx = 0; gr1->gr_mem[gr1_ndx] != NULL;
+                   gr1_ndx++) {
+                       for (gr2_ndx = 0; gr2->gr_mem[gr2_ndx] != NULL;
+                           gr2_ndx++)
+                               if (strcmp(gr1->gr_mem[gr1_ndx],
+                                   gr2->gr_mem[gr2_ndx]) == 0) {
                                        found = true;
                                        break;
                                }
-                       if (! found) {
-                               equal = false;
-                               break;
-                       }
+                       if (!found)
+                               return (false);
                }
 
                /* Check that group2 does not have more members than group1. */
-               if (gr2->gr_mem[gr1Ndx] != NULL)
-                       equal = false;
+               if (gr2->gr_mem[gr1_ndx] != NULL)
+                       return (false);
        }
 
-       return (equal);
+       return (true);
 }
 
-
 /*
  * Make a group line out of a struct group.
  */
@@ -89,82 +397,84 @@ char *
 gr_make(const struct group *gr)
 {
        char *line;
+       size_t line_size;
        int ndx;
-       size_t lineSize;
 
        /* Calculate the length of the group line. */
-       lineSize = snprintf(NULL, 0, GroupLineFormat, gr->gr_name,
+       line_size = snprintf(NULL, 0, group_line_format, gr->gr_name,
            gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
-       for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
-               lineSize += strlen(gr->gr_mem[ndx]) + 1;
-       if (ndx > 0)
-               lineSize--;
+       if (gr->gr_mem != NULL) {
+               for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
+                       line_size += strlen(gr->gr_mem[ndx]) + 1;
+               if (ndx > 0)
+                       line_size--;
+       }
 
        /* Create the group line and fill it. */
-       if ((line = malloc(lineSize)) == NULL)
+       if ((line = malloc(line_size)) == NULL)
                return (NULL);
-       lineSize = snprintf(line, lineSize, GroupLineFormat, gr->gr_name,
-           gr->gr_passwd, (uintmax_t)gr->gr_gid);
-       for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
-               strcat(line, gr->gr_mem[ndx]);
-               if (gr->gr_mem[ndx + 1] != NULL)
-                       strcat(line, ",");
-       }
+       snprintf(line, line_size, group_line_format, gr->gr_name, gr->gr_passwd,
+           (uintmax_t)gr->gr_gid);
+       if (gr->gr_mem != NULL)
+               for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
+                       strcat(line, gr->gr_mem[ndx]);
+                       if (gr->gr_mem[ndx + 1] != NULL)
+                               strcat(line, ",");
+               }
 
        return (line);
 }
 
-
 /*
  * Duplicate a struct group.
  */
 struct group *
 gr_dup(const struct group *gr)
 {
-       int ndx;
-       int numMem;
+       char *dst;
        size_t len;
-       struct group *ngr;
+       struct group_storage *gs;
+       int ndx;
+       int num_mem;
 
-       /* Calculate size of group. */
-       len = sizeof(*gr) +
-           (gr->gr_name != NULL ? strlen(gr->gr_name) + 1 : 0) +
-           (gr->gr_passwd != NULL ? strlen(gr->gr_passwd) + 1 : 0);
-       numMem = 0;
+       /* Calculate size of the group. */
+       len = sizeof(*gs);
+       if (gr->gr_name != NULL)
+               len += strlen(gr->gr_name) + 1;
+       if (gr->gr_passwd != NULL)
+               len += strlen(gr->gr_passwd) + 1;
        if (gr->gr_mem != NULL) {
-               for (; gr->gr_mem[numMem] != NULL; numMem++)
-                       len += strlen(gr->gr_mem[numMem]) + 1;
-               len += (numMem + 1) * sizeof(*(gr->gr_mem));
-       }
+               for (num_mem = 0; gr->gr_mem[num_mem] != NULL; num_mem++)
+                       len += strlen(gr->gr_mem[num_mem]) + 1;
+               len += (num_mem + 1) * sizeof(*gr->gr_mem);
+       } else
+               num_mem = -1;
 
        /* Create new group and copy old group into it. */
-       if ((ngr = calloc(1, len)) == NULL)
+       if ((gs = calloc(1, len)) == NULL)
                return (NULL);
-       len = sizeof(*ngr);
-       ngr->gr_gid = gr->gr_gid;
+       dst = (char *)&gs->members[num_mem + 1];
        if (gr->gr_name != NULL) {
-               ngr->gr_name = (char *)ngr + len;
-               len += sprintf(ngr->gr_name, "%s", gr->gr_name) + 1;
+               gs->gr.gr_name = dst;
+               dst = stpcpy(gs->gr.gr_name, gr->gr_name) + 1;
        }
        if (gr->gr_passwd != NULL) {
-               ngr->gr_passwd = (char *)ngr + len;
-               len += sprintf(ngr->gr_passwd, "%s", gr->gr_passwd) + 1;
+               gs->gr.gr_passwd = dst;
+               dst = stpcpy(gs->gr.gr_passwd, gr->gr_passwd) + 1;
        }
+       gs->gr.gr_gid = gr->gr_gid;
        if (gr->gr_mem != NULL) {
-               ngr->gr_mem = (char **)((char *)ngr + len);
-               len += (numMem + 1) * sizeof(*(ngr->gr_mem));
-               for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
-                       ngr->gr_mem[ndx] = (char *)ngr + len;
-                       len += sprintf(ngr->gr_mem[ndx], "%s",
-                           gr->gr_mem[ndx]) + 1;
+               gs->gr.gr_mem = gs->members;
+               for (ndx = 0; ndx < num_mem; ndx++) {
+                       gs->gr.gr_mem[ndx] = dst;
+                       dst = stpcpy(gs->gr.gr_mem[ndx], gr->gr_mem[ndx]) + 1;
                }
-               ngr->gr_mem[ndx] = NULL;
+               gs->gr.gr_mem[ndx] = NULL;
        }
 
-       return (ngr);
+       return (&gs->gr);
 }
 
-
 /*
  * Scan a line and place it into a group structure.
  */
@@ -180,14 +490,14 @@ __gr_scan(char *line, struct group *gr)
                return (false);
        *loc = '\0';
        gr->gr_passwd = loc + 1;
-       if (*(gr->gr_passwd) == ':')
-               *(gr->gr_passwd) = '\0';
+       if (*gr->gr_passwd == ':')
+               *gr->gr_passwd = '\0';
        else {
                if ((loc = strchr(loc + 1, ':')) == NULL)
                        return (false);
                *loc = '\0';
        }
-       if (sscanf(loc + 1, "%u", &(gr->gr_gid)) != 1)
+       if (sscanf(loc + 1, "%u", &gr->gr_gid) != 1)
                return (false);
 
        /* Assign member information to structure. */
@@ -195,40 +505,42 @@ __gr_scan(char *line, struct group *gr)
                return (false);
        line = loc + 1;
        gr->gr_mem = NULL;
-       if (*line != '\0') {
-               ndx = 0;
+       ndx = 0;
+       do {
+               gr->gr_mem = reallocf(gr->gr_mem, sizeof(*gr->gr_mem) *
+                   (ndx + 1));
+               if (gr->gr_mem == NULL)
+                       return (false);
+
+               /* Skip locations without members (i.e., empty string). */
                do {
-                       if ((gr->gr_mem = reallocf(gr->gr_mem,
-                           sizeof(*(gr->gr_mem)) * (ndx + 1))) == NULL)
-                               return (false);
                        gr->gr_mem[ndx] = strsep(&line, ",");
-               } while (gr->gr_mem[ndx++] != NULL);
-       }
+               } while (gr->gr_mem[ndx] != NULL && *gr->gr_mem[ndx] == '\0');
+       } while (gr->gr_mem[ndx++] != NULL);
 
        return (true);
 }
 
-
 /*
  * Create a struct group from a line.
  */
 struct group *
 gr_scan(const char *line)
 {
-       char *lineCopy;
-       struct group *newGr;
        struct group gr;
+       char *line_copy;
+       struct group *new_gr;
 
-       if ((lineCopy = strdup(line)) == NULL)
+       if ((line_copy = strdup(line)) == NULL)
                return (NULL);
-       if (!__gr_scan(lineCopy, &gr)) {
-               free(lineCopy);
+       if (!__gr_scan(line_copy, &gr)) {
+               free(line_copy);
                return (NULL);
        }
-       newGr = gr_dup(&gr);
-       free(lineCopy);
+       new_gr = gr_dup(&gr);
+       free(line_copy);
        if (gr.gr_mem != NULL)
                free(gr.gr_mem);
 
-       return (newGr);
+       return (new_gr);
 }